1. Field
The described technology relates generally to a thin film transistor array panel and a manufacturing method thereof.
2. Description of Related Art
A liquid crystal display (LCD) is a flat panel display that is constituted by two array panels with electrodes and a liquid crystal layer interposed therebetween to control the amount of light transmitted by rearranging liquid crystal molecules of a liquid crystal layer by applying a signal to the electrodes.
A plurality of pixel electrodes are arranged in a matrix format on a thin film transistor array panel formed of two array panels. One common electrode covers the entire array panel on a common electrode array panel. Images are displayed on the liquid crystal display (LCD) by applying a different voltage to each pixel electrode. To achieve this purpose, a thin film transistor having three terminals for switching the voltage applied to the pixel electrode is connected to the pixel electrode, and a gate line for transmitting a signal for controlling the thin film transistor and a data line for transmitting a voltage to be applied to the pixel electrode are installed on the thin film transistor array panel.
The gate line transmits a gate signal generated by a gate driving circuit of a gate driving chip, and the data line transmits a data voltage generated by a data driving circuit of a data driving chip. The chip on glass (COG) mounting method for directly bonding the gate driving chip or the data driving chip to the thin film transistor array panel and the film on glass (FOG) mounting method for directly bonding the flexible printed circuit (FPC) on the thin film transistor array panel are applied.
The COG and FOG mounting methods use anisotropic conductive films to electrically and mechanically connect the driving chip and the flexible printed circuit (FPC) to the thin film transistor array panel.
In addition, it is possible to form a gate driving pad contact hole of the thin film transistor array panel connected to the gate driving chip and a semiconductor layer with a single mask, thereby reducing the manufacturing process and production costs.
In this instance, when bubbles are formed in a halftone photosensitive film for forming a gate driving pad contact hole and a semiconductor layer on the gate insulating layer, at a part corresponding to a sustain electrode, the bubbles may cause holes to be formed within the halftone photosensitive film, and a phenomenon may occur in which the sustain electrode and the drain electrode are shorted to look like a black dot because of the holes. Further, holes may also be formed in the halftone photosensitive film because of foreign particles introduced at a part of the semiconductor layer corresponding to the sustain electrode when the semiconductor layer is deposited, so the sustain electrode and the drain electrode may be shorted to look like a black dot because of these holes.
This is because a single halftone mask is used to form the gate driving pad contact hole and the semiconductor layer. The thickness of the halftone photosensitive film formed on the part corresponding to the sustain electrode is less than 9000 Å thick, so the holes for exposing the sustain electrode to the halftone photosensitive film may be generated because of the foreign particles that are greater than 9000 Å or the bubbles.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.